> At least in the US, there's a fairly large industry built around mold testing & remediation

Be aware that's there's also a very large industry built around selling people unnecessary or non-standard mold tests (which always come back positive) along with "expert consultation services" and then refer you to local remediation companies for a very large kickback.

Mold scares are big business. If you visit a company's website and they have long lists of non-specific illnesses or make claims that nearly every disease could be caused by mold, don't engage with them. If you contact them at all or buy their services you're likely to end up in their leads database and be marketed to until the end of time. There is a lot of money in scaring people into unnecessary mold testing and remediation services.